The discovery of high temperature superconductivity in 1986 stimulated an enormous research activity around the world in physics, chemistry as well as in materials science. The synthesis, the analysis and the understanding of superconducting Cu-based mixed oxides are difficult scientific challenges. Moreover, the fabrication of superconducting ceramics and of thin films and devices poses new technological problems. Actually, the complexity of these materials is one of the main reasons of their relatively slow appearence on the world market. A successful research in the field of High-Tc supercon­ ductivity strongly demands a deep cooperation between scientists from various fields. This is exactly why High-Tc superconductivity became a crystallization center or a nucleus for scientific cooperation of researchers from various fields and from different countries. The numerous international conferences on High-Tc materials often unify physicist, chemists and materials scientists, theoreticians as well as experimentalists, aiming to dis­ cuss and to find the optimum solution for important problems in this field. This idea was the reason why the Department of Inorganic Chemistry of the Moscow State University organized in 1989 the I-st International Workshop "Chemistry and Technology of High­ Tc materials MSU-HTSC-I". These workshops, organised every other year, allowed to establish and develop scientific cooperation between Western and Russian scientists. In 1998 the 5-th International Workshop on "High Temperature Superconductors and Novel Inorganic Materials Engineering - MSU-HTSC-V" was organized.